This study looks at a treatment called transcutaneous auricular vagus nerve stimulation, or taVNS. taVNS uses a small device worn on the ear to gently stimulate a nerve. Researchers want to find out if this treatment is safe and well-tolerated for people who recently had a spinal cord injury (SCI).

This study will also help researchers learn whether taVNS can be safely added to standard mobility therapy, and whether it might help improve mobility.

This study has two main goals:

1. To find out whether taVNS is safe and comfortable for people with a recent spinal cord injury.
2. To get information on whether taVNS may help improve mobility when compared to people who completed rehabilitation before this study started.

This study has two parts.

In the first part, participants will wear the taVNS device once for a short period of time. During this part investigators will measure how participant's heart rate and blood pressure may change before, during, and after the stimulation. Investigators will also ask about how the stimulation made participants feel.

In the second part, participants will wear the taVNS device for a short time right before a mobility therapy session. During this part investigators will measure how participants heart rate and blood pressure may change before, during, and after the stimulation and during and after the walking therapy. Investigators will also ask about how the stimulation made participants feel.

Inclusion Criteria:

• Phase 1 Age 18 years older SCI (traumatic or non traumatic) undergoing initial inpatient rehabilitation for the SCI Any AIS severity level (A, B, C, D)
• Phase 2 Completed phase I Participant willing to complete phase II Study physician approves participation in phase II Receives intensive gait training as a part of the care plan

Exclusion Criteria:

• Phase 1 Age >89 years Pregnant Implanted medical device (e.g. pacemaker, cochlear implant) epilepsy Parkinson's Disease Multiple Sclerosis cerebral shunts documented arrhythmia Ear skin irritation or damage at the electrode contact location intracranial metal implants
• Phase 2 no exclusion criteria for those who meet inclusion criteria

This is an internally funded study with limited personnel support. Adequate preparation of the data to ensure seamless and rigorous sharing cannot be guaranteed at the time of registration. The investigators may update the plan to share IPD in the future if additional personnel support becomes available.